gistfile1.js

    // In lieu of unit tests:
    var c1 = window.c1 = Cursor.build(window.App);
    var c2 = window.c2 = Cursor.build(window.App);
    console.assert(c1.value === c2.value);
    console.assert(c1.onChange === c2.onChange);
    console.assert(c1 === c2);

    var c10 = c1.refine('very', 'deeply', 'nested', 'counts', '0');
    var c20 = c2.refine('very', 'deeply', 'nested', 'counts', '0');
    console.assert(c10.value === c20.value);
    console.assert(c10.onChange === c20.onChange);
    console.assert(c10 === c20);

    var c20b = c2.refine('very', 'deeply', 'nested', 'counts', '0');
    console.assert(c20b.value === c20.value);
    console.assert(c20b.onChange === c20.onChange);
    console.assert(c20b === c20);